Hydraulic shock absorber



June 25, 1935. pic I 2,005,750

HYDRAULIC snocx ABSORBER I Filed April 29, 1953 2 Sheets-Sheet l EALPH E P50.

June 25, 1935.

R. F. PEO

HYDRAULIC SHOCK ABSORBER Filed April 29, 1933 2. Sheets-Sheet 2 EALPH F.

Patented June 25, 1935 PATENT OFFICE 2,005,150 HYDRAULIC SHOCK sssonsna Ralph F. Peo, Buffalo, N. Y., assignor to Houde Engineering Corporation, Buffalo, N. Y., a corporation of New York Application April 29, 1933, Serial No. 668,532

13 Claim.

This invention relates to hydraulic shock absorbers and particularly to improved valve structures therefor for controlling the bypassage of resistance fluid from one side of the piston struc- 5 ture to the other during operation of the shock absorber for determining shock absorbing resistance.

An important object of the invention is to provide simpler, more economically manufactured and assembled, and more eflicient valve structure which may be readily adjusted and set manually from the exterior of the shock absorber and which is then thermostatically adjusted for control of the bypassage resistance to fluid flow in accordance with variations in temperature and resulting change in the viscosity of the fluid.

A further object is to provide valve structure comprising two valve members having ports cooperable for control of the bypassage flow, with 0 one of said members manually adjustable from the exterior of the shock absorber, and the other member thermostatically adjusted.

Another object is'to provide a valve structure which may be readilyassembled within the piston structure of the shock absorber and in which the thermostat element for adjusting one of the valve members is housed to be accurately guided for control of the valve member and to be protected against fluid pressure, stresses and strain so that it may freely function to accurately control the valving adjustment in accordance with change in temperature of the fiuid.

Still a further object is to provide a housing or container for the thermostat element, into which such element and the valve member to be controlled thereby may be accurately assembled before the housing is applied in the shock absorber for association of the thermostatically controlled valve member with the manually adjustable valve member.

The above enumerated and other features of the invention are shown incorporated in the structure disclosed on the drawings in which drawings Figure l is a vertical section through the axis of the shock absorber on plane 1-1 of Figure 2;

Figure 2 is a section on plane IIII of Figure 1;

Figure 3 is a section on plane III-III of Figure 1;

Figure 4 is an inner end view of the piston structure.

The structure shown comprises a base I! having the cylindrical flange or wall It extending therefrom and having laterally extending wings l2 with bolt holes i3 for securing the base structure to a support such as the chassis of an automotive vehicle. Fitting within the cylindrical wall H and abutting the base end is a cylindrical ring It having the upper and lower partition walls or lugs l5 and i8 extending radially therefrom 5 and preferably integral with thering ll, this structure being rigidly secured to the base Ill against rotation by means of pins l1 anchored in the base and extending through the walls I! and I6. A wall I! tits into the outer end 0! the 10 cylindrical wall II and is held in abutting engagement with the outer faces of the ring it and partition walls and this wall It is secured by a circular nut l9 threading into the wall II. A. cap structure 20 has threaded engagement with the outer side of the wall II and is locked by a locking ring. 2| between which and the cap packing material 22 is inserted to prevent leakage.

The piston structure comprises the cylindrical hub 23 having piston wings or vanes 24 and 25 extending radially therefrom in opposite directions, and a driving shaft 20 extending axially from the hub. The hub and the wings extend axially between the base I. and the wall II and the outer surfaces of the wings engage with the inner cylindrical surface of the ring ll. The shaft has bearing in the wall II and the extension 21 thereon, the shaft extending through the'outer :wall of the cap 20 and is adapted to receive the arm or lever 28 whose end is connected usually with the axle of the automotive vehicle. Packing material 29 is inserted between the cap 20 and the end of the bearing extension 21 to prevent leakage, the base enclosed by the cap and the wall It and bearing extension 21 forming a reservoir or replenishing chamber 30 into which the resistance fluid may be charged through an opening adapted to be closed by a plug 3 l The partition and walls I! and I! are engaged at their inner ends by the cylindrical surface of the piston structure hub and the partitions and the piston structure divide the space within the ring it into high pressure chambers 3|, 3| and low pressure chambers 32, 32. Each of the piston vanes has a bypge 33 therethrough providing a seat 14 for a valve 35 such as a ball, the valves being arranged so that the resistance fluld may flow from the low pressure chambers into the high pressure chambers during low pressure movement of the piston structure, as when the vehicle chassis and axle move toward each other, but so that the valves will close these bypasses against flow from the high pressure to the low pressure chambers during the high pressure or rebound movement of the vehicle, as when the c assis and axle are separated by the spring recoil the viscosity the fluid so that the shock ab vsorbet-resistancewillremsinuninnuen'cedbysuch viscosity change. This automatic control is'b'y means of valvemechanism which will now be described. The shaft has the axial borell' therethrough which at its inner end is slightly enlarged in diameter to provide the cylindrical valve chamber 3'! which is connected by the ducts II and II with the high pressure chambers II 1 SI for setting oi the valve ports for fluid flow for and ll, these ducts extending radially through the piston hub 23. Within the valve chamber 31 hthe-outer member or frame 3! which is cylindrical and has the cylindrical bore 40 for receiving and seating the inner valve member M. The

valve member "has the circumierentially extending channel 82 in its outer side forming a connection. between the inner ends 0! the ducts 3t and the member II has the port 41 thereflinough communicating with, the channel, the

being a elrcinnterentially extending valvemember 4| has-a port It, as a circumterentially extending slot for u to control the fluid now; 'lhe'innor valve member 4! isshown to be oi construction-lemming a passage commnnicating with the u andincluded in the circuitwf;

"In the inner end at piston. structure hub 23 is the cylindrical pocket fliwhlchis concentric with the valve chamber". Thispocket serves to receivejand-house'the thermostat structure for controllingthuvalves; The structure comprises a 48 which may readily be termed oi the cup being 01' such outer diameter as to trictionally lit into the pocket 46. Within thecup is the spiral thermostat coil ll formed'troma strip or! bi-metal whose metal layers area! material-o! dlilerent expansion coeihcient,= {The outer end 4. of the coil is anchored to the'cumthe end being deflected to extend radially into a slot 40 formed in the cylindrical wall of the cup. The cup is inserted in the pocket Ill with its bottom side outso as to form a closure lorthe pocket. The cup receives the outer end of the tubular inner valve member and inits bottom has the opening ll registering with the bore of the valve member. The depth or axial width oi. the cup isless than .the'depth oi the pocket 48 so that after insertion of the cup in the pocket there will remain a shallow space or chamber between the cup bottom and the base II which space or chamber is connected by ports 52 and 82' with the low pressure chambers "and 3! respectiv ly. the bypassagc from the high pressure chambers to the low pressure chambers thus in" cluding the ducts It and It. the channel t2, the valve ports and 44, the bore of valve It; the opening Bl through the cup bottom, the chamberiLandtheports I! and 52'. I Fm inner and I3 of the thermostat coil is deilectcd radially and is received in the longitudinal slot It in the inner valve member 4! so that dur= ing winding and unwinding movement of the coil in response to temperature change the inner valve member will bemtated ioradiustment of annular shoulder .51.

its port 44 relative to the port 43 in the outer valve member.

The outer valve member 39 has a stem 55 extending axially therefrom and through the bore 36 in the piston shaft, the outer end of the stem being threaded for the reception of a nut 56, the outer end of the valve member seating against the By loosening the nut 56 the stem 56 may be turned for rotary movement of the outer valve member 3! and setting of its port 43 relative to the inner valve port 44. The outer end of the stem may be provided with a screw driver slot 58 for facilitating turning thereof and a spring washer I8 is preferably inserted between the nut and the shaft so that after ad justment of the outer valve member and tightening of the nut the adjustment will remain fixed.

After assembly 01' the shock absorber, manual adjustment is made 0! the outer valve member matically rotate the inner valve member for less overlap of its port 44 with the port 43 otthe outer valve member so that the flow or shock absorber resistance will 'remain'the same as that under normal temperature conditions. It the temperature should become reduced below normal and the fluid become more viscous, the thermostat coil will respond to adjust the inner valve f member for greater port overlap to allow tor increasing viscosity and to maintain the shock absorber rcsistancevpractically normal.

During the rebound stroke 01 the shock absorber, that is, when the vehicle springs tend to rapidly recoil to move the vehicle body away from the axles, the piston structure will rotate in counterclockwise direction (Fig. 2) during which rotation the bypassages 33 will. be held closed by the ball valves so that the only escape of fluid from the high pressure chambers to the low pressure chambers will be through. the restricted passage provided by the overlapping p rts 48 and N, the flow being from the high pressure chambers 3|, 3| through the ducts a, I" to the Chan'- pressure chambers will be through the bi-passages 33, the remaining flow being through the passage controlled by the valve ports I! and 44.

The pressure or working chambers oi the shock absorber are kept filled with fluid from the reser-.-, voir 3Q, replenishing fluid being drawn into the bottom of each of the lower chambers through a passage 80 in the wall I! and past a ball valve GI,

flow in reverse direction being prevented by the valve. Any collected gases or air may escape from the tops of the'upper chambers by way of restricted slits or grooves 62- provided in plugs t3 extending through the wall I8. v

By providing in the piston structure hub n. cy-

lindrical pocket 01' comparatively large diameter,-

a large spiral thermostat coil having many turns will be accommodated which will be very sensitive to temperature changes and powerful to accurately adjust the bypassage resistance in ac-' cordance with temperature and resulting viscosity changes. Furthermore, the thermostat coil will have a comparatively large range of angular ad-' justment oi the inner valve member. The container cup for the coil will protect the coil against injury before assembly in the piston pocket and after assembly the coil will be entirely housed and protected against injury and tampering and the cup and adjacent wall of the piston hub will accurately guide the winding and unwinding move-, ment of the coil so that the turning resistance of the valve will be reduced to a minimum.

I am aware that many changes may be made and numerous details of construction may be varied through a wide range without departing from the principles of this invention, and I, therefore, do not purpose limiting the patent granted hereon otherwise than necessitated by the prior art.

I claim as my invention:

1. In a hydraulic, shock absorber comprising a housing having a space for containing resistance fluid, a piston structure operable "within said space against the resistance flow of the fluid, a bypass trom one side of the piston structure to the other, a. valve seat frame having a port interposed in said bypass, a valve movable on said valve seat frame and having a port for cooperating with said frame port to control the flow or fluid through the bypass, means for manually adhaving a space for containing resistance fluid,-

lusting said seat frame for setting of its port relative to the valve port, and a thermostat connected with the valve to automatically set its port relative to the frame port in accordance with the changes in temperature of the fluid.

2. In a-hydraulic shock absorber, a housing a piston structure operable within said space against the resistance flow of said fluid, a bypass.

from one side of the piston structure to the other, a valve chamber interposed in said bypass, outer and inner valve members in said chamber having ports for cooperating to control the flow through said bypass, means for manually adjusting one of said valve members from the exterior of the shock absorber for setting of said ports, and a bi-metal thermostat structure for adjusting the other valve member for automatic setting of said ports for control of the e flow in accordance with the change in temperature of the fluid,

3. In a hydraulic shock absorber, a housing having a space for containing resistance fluid, a piston structure operable within said space against the resistance flow ofsaid fluid. a bypass frcm one side of the pistonstructure to the other, and a valve assembly for controlling B810. bypass, saidvalve assembly comprising a ported outer valve member and a ported inner valve member, means whereby said outer valve element is manually adjustable for setting of the valve ports, and a thermostat element ior automatically adjusting the inner valve element for setting of said ports in accordance with variations for manually moving one of said valve member: for relative setting of said ports, and a thermostat element for automatically moving the other valve member for relative adjustment of said ports in accordance with temperature change of the fluid.

5. In a'hydraulic resistance device compris- I ing a housing for containing resistance fluid and provided with a piston structure operable against the resistance flow of the fluid and a bypass from one side of the piston structure to the other, a valve chamber intersecting said bypass, a valve assembly comprising outer and inner concentric valve members having ports cooperabie to control the bypassage flow. means for manually moving one of said valve members for relative setting of said ports, and thermostat means for automatically moving the other valve'membar for relative setting of said ports in momance with changes in temperature of the fluid.

,6. In a hydraulic shock absorber comprising a housing forming a chamber for containing re sistance fluid, a piston operable within said housing against the resistance flow of 'the fluid, a fluid bypass through said piston, said piston having an axial bore intersecting said bypass, a rotary valve seated in said bore and having a port, said bore being enlarged at one end to form a cylindrical pocket, and a spiral thermostat element in said pocket connected to rotate said valve for setting of its port in said bypass in accordance with change in temperature of the fluid. 4

7. A hydraulic shock absorber comprising a. housing forming a chamber for containing resistance fluid, a piston hub in said chamber and a vane extending therefrom, an operating shaft extending from the piston hub to the exterior of the housing, said shaft and hub having an axial bore therethrough, a bypass through the hub, a cylindrical outer valve member within said bore having a port communicating with said bypass, an inner valve member seated in said outer valve member and having a port for cooperating with the port of the outer member to control the flow through the bypass, a stem ex-- tending from said outer valve member and being manually operable for rotation of said outer valve member for relative setting of said ports, the inner end of said bore' being enlargedto form a pocket, and a thermostat coil in said pocket connected to rotate said inner valve memher for setting of said ports in accordance with change in the temperature of the fluid.

8. A hydraulic shock absorber comprising a housing forming a .chamber for containing resistance fluid, a piston hub in said chamber and a vane extending therefrom, an operating shaft extending from the piston hub to the exterior of the housing, said shaft and hub having an axial bore therethrough, a bypass through the hub, a cylindrical outer valve member within said bore having a port communicating with said bypass. an inner valve member seated in said outer valve member and having a port for cooperating with the port of the outer member to control the flow through the bypassage, a stem extending from said outer valvemember through said bore and being manually operable for rotation of said outer valve member for relative setting of said ports, the inner end of said bore being enlarged said inner valve member for rotating said inner valve member for setting of said ports for adjusting the bypass flow in accordance with change in temperature of the fluid.

' 9. A hydraulic shock absorber comprising a housing forming a chamber for containing resistance fluid, a piston structure operable within said housing against the resistance flow of said fluid, a fluid bypass through said piston structure, a valve extending axially in said piston structure and having a port for controlling said bypass, said piston structure having a cylindrical pocket concentric with said valve, a cylindrical cup seated in said pocket with its bottom forming a closure therefor, and a thermostat coil in said cup connected with said valve for automatic adjustment thereof in accordance with change in temperature 01' the fluid.

10. In a hydraulic shock absorber, a housing, a piston structure operable within said housing, said housing and piston structure defining working chambers at opposite sides of the piston structure for hydraulic fluid, a passageway connecting said working chambers, a recess in said passageway, valve members in said recess having ports co-operable to control the flow through said passage, means for manually setting one of said valve members, and thermostatic means in said recess for automatically adjusting said other valve member.

11. In a hydraulic shock absorber, a housing, a piston structure operable within said housing, said housing and piston structure defining working chambers at opposite sides of the piston structure for hydraulic fluid, a passageway connecting said working chambers, a pair or rela= tively rotatable valve members having ports arranged for variable overlap to control the flow of fluid through said passage, one of said valve members being manually adjustable from the exterior oi the shock absorber, and a thermostat element within the shock absorber for adjusting the other valve member.

12. In a hydraulic shock absorber, a housing, a piston structure operable within said housing to displace hydraulic fluid therein, said housing and piston structure defining working chambers at opposite sides of the piston structure, a passageway connecting said chambers, a valve and a .valve seat therefor insaid passage, means operable from the exterior of the housing for adjusting said valve seat relative to said valve, and a thermostat coil within said housing for automatically adjusting said valve relative to said seat.

13. In a hydraulic shock absorber, a housing, a

piston structure operable in said housing to dis- 7 place hydraulic fluid therein, said housing and piston structure defining working chambers at opposite sides of the piston structure, a passageway connecting said chambers, two telescopically engaged valve members interposed in said passage and having ports arranged for variable overlap to control the flow through said passage, means,

whereby one or said valve members may be manually shifted from the exterior oi the shock absorber for setting of said ports, and a thermostat conflned within said housing for shifting the other valve member for automatic adjustment of said ports in correspondence with change in temperature of the fluid.

RALPH F. PEO. 

